Air-operated grease pump



Aug. 19, 1930. B. B. Dom 1,773,423

AIR OPEATED GREASE PUMP Filed June 1l. 1929 Patented Aug. 19, 1930 BERNARD B. DOLLY, oF coT'roNWoon, ARIZONA AIR-OPERATED VAppli-cation filed Julie 11,

This; invention relates to an air operated grease pump, and it has for its object to provide a struc-ture adapted to be operated by the sources ofcompressed air such as are 5 commonly found in garages, service stations, and the like, and which will function to discharge grease, at very high pressure, into the bearings of mechanisms that are to be lubricated, such as automobiles, for example.

It is well known that mos-t bearings can be lubricated with grease under a relatively low pressure, but occasionally a bearing is encountered in which grease and dirthas caked and hadened in such manner that only 15 very high pressure will drive the fresh grease thereinto.

The device of the present invention is particularly designed to take care of this situation.

The ligure shown in the accompanying drawing is a sectional view of a grease pump constructed in accordance with the invention.

1n the drawing, 5 designates a relatively large grease cylinder provided, at its forward end, with a removable cap 6, through which the chamber may be filled with grease. A plunger 7 is mounted to travel in the cylinder. Asecond cylinder 8 has a piston 9 disposed therein, which operates the high pressure plunger 10, the latter being disposed to travel in the high pr-essure grease chamber 11. Compressed air, say at eighty pounds pressure, is delivered from the supply hose 12 t0l air conduit 13. If the triple port valve or cock 111 be momentarily turned so that its central port 14a lies vertically, air will pass into the cylinder 8, at the left hand side of the piston 9, and force the high pressure' plunger toward the right, ejecting air from the high pressure grease chamber 11.

The valve or cock `14 isthen turned so that its central port lies horizontal. This permits the air-in chamber 15, of cylinder 5, to waste through ports 16, 14'QL and 17, while checking the entry of more air to conduit 13.

This will permit the opera-tor to unscrew the cap 6, and fill the grease chamber 5a with grease, the plunger 7' being forced back to the left hand end of the cylinder by the packing of the grease into grease chamber 5a.

GREASE PUMP 1929; serial No. 37oo3o.

After the cap has been restoredto its former il Some of the grease will also enter the high pressure grease chamber 11 and force the lunger 9 toward the left, until it is stopped ya stop rodQO. 1f the entry of the .grease to the bearing to be lubricated offers less resistance than can be overcome by the eighty pounds pressure imposed upon plunger 7, greasel will be delivered directly to said bearing, but if the bearingis caked sothat the eighty pounds pressure will not force the grease thereinto, a much higher pressure may -K u be imposed upon` the grease inthe discharge hose, by turning the cock 14 to aposition where its central port ylst?l lies vertical. The air `pressure will .then passthrough conduit 13 to the left hand sidev of the piston 9, and will force grease from they high pressure greasechamber into the discharge hose at a pressure upto twenty-five'hundredfpounds, if need be, because eighty poundsv vpressure against piston `'9 will createl pressure in the chamber 11, in the relation'thatthe square of the diameter'of theA piston 9 bears to the square of thedianieter of the plunger or piston 10. vThis operation may be repeated as often as desired by simply turning cock 14 back to the pOSition shown in the drawing, 'A

and then to upright position again.

An` indicator rod 21 travels out with the piston `9 tofindicatethe amount of' grease that the booster ory high pressureplunger is delivering. V.Thecapcarries an indicator consisting of a rod 22, having nuts or other head ing elements 23 uponlits opposite ends.v A spring 211 lnormally holds this rod inV retracted position, but when the grease chamber A5a becomes so nearly exhausted kof grease that the projection 7 a onthe piston 9, strikes the head'or nut 23 'of rod 22, the latter willv be forced tothe right against the action of the spring 241y and indicate upon the exterior of cap 6 that the grease chamber is so nearly exhausted as to require refilling.

It is to be understood that the invention is not limited to the precise construction set fort-h, it being clear that many changes will readily suggest themselves to persons skilled in the art, even though the principles of operation 'remain the same. For example, the relative size of parts may be changed and the various pistons may be provided with cup leathers on either or both sides, while the 'pis-V ton or plunger l0 may be provided with a leather washer or cap upon its forward end.

Having described my invention, what I claim is:

I 1. A device lofthe vcharacter described,

Vwith the' high pressure cylinder, a check valve operating substantially at right angles to the axes Vof theA said two cylinders, and disposed 'between the lirst nained cylinder and the grease discharge' line, an air supply conduit, there being ports associated with said conduit'and cylinders, and a three-way valve associated with said conduit and cylinders and operating when turned to one position to admit air to the first named cylinder and vent the second named cylinder to the atmosphere, and when turned to another position to admit air to the second cylinder, and when moved to a third position to vent theflrst named cylinder to the atmosphere.

2. A device of the character described, comprising a mainfgrease cylinder of relatively large diameter and having a piston tting and sliding therein and having a revalve through the rear wall of the main cylinder to the interior of the cylinder and there being a port diametrically opposite the last named port and leading from the seat of the valve directly through the rear wall of the rst named main cylinder, to the atmosphere, the arrangement of said ports and the arrangement of the ports of thethree-way valve being such that when said valve is turned to one position it admits air to the first named' cylinder and vents the second cylinder to the atmosphere, and when turned to "another position it admits air to the second cylinder and cuts off the air to the first named cylinder, and when moved to a third position, it rvents the `first' named Acylinder to the yatmospherefand*cuts olf the air to the second named cylinder.

In testimony whereof vhe'aixes his signature. x

BERNARD B. DOLLY.

movableforward end, a second cylinder in parallelism with the lirst named cylinder and at one side thereof, a piston therein, a small diameter high pressure grease chamber in y alignment with the said second cy1inder,'a plunger carried by the second namedv piston andoperating inthe high pressure grease chamber,a grease discharging line in axial alignment with the high pressure cylinder, a VYspring actuated check valvev operating substant-ially at right angles to the axes of the said tvvo cylinders and disposed between the first named cylinder and the grease discharge line, an air conduit Aleading transversely across the rear end of the first named cylinder and directly into the second named cylinder in the rear of the piston therein, a threeway valve in said conduit, there being ra port leading directly from the seat of said ioo 

